The main paper goes into the detail on page 2. The cables were on beam path.

“The only hypothesis the committee could develop that provides a plausible but unprovable answer to all these questions and the observed socket failure pattern is that the socket zinc creep was unexpectedly accelerated in the Arecibo Telescope’s uniquely powerful electromagnetic radiation environment. The Arecibo Telescope cables were suspended across the beam of “the most powerful radio transmitter on Earth. National Academies of Sciences, Engineering, and Medicine. 2024. Failure Analysis of the Arecibo Observatory 305-Meter Telescope Collapse. Washington, DC: The National Academies Press. https://doi.org/10.17226/26982.”

> I presume we aren't using most bridges as interstellar antennas.

any like area of metal will receive as much interstellar emissions but I guess they did run a MW transmitter sometimes.

Arecibo didn’t know it was a telescope. Every wire in the world is an antenna.

No, but there is a lot of potential for large structures to act like an accidental antenna and/or receive low level voltages from the environment or other equipment.

Likely won't matter in most cases, but there could be a few disasters waiting around.

That’s what the government (… and most rational people) wants you to think.